SURFACE WATER FLOW AND SEEPAGE INTO A RIVERBED IN A BLANCHED REGION OF THE OTA RIVER

Abstract

The water exchange through riverbeds near a branch of the Ota River estuary was investigated using a seepage meter which can measure the both of surface water infiltration and subsurface water discharge. Surface water infiltration to riverbeds was prominent in neap tide, and the water velocity in spring tide fluctuates significantly because of the density difference between surface water and subsurface water. Surface water flow and water surface gradient in the branch region were investigated, and the tidal variation of water flow distribution and material transport depend on the water surface gradient of downstream direction and transverse direction.